A planar Fourier capture array (PFCA) is an image-sensing device that employs an array of angle-sensitive pixels to obviate the needs for a mirror, lens, focal length, or moving parts. The pixel array can be made using standard integrated-circuit fabrication processes. As a consequence of these advantages, PFCAs can be made much smaller and less expensive than the smallest focusing camera.
Some PFCAs use a near-filed diffraction effect known as the “Talbot effect” to create the angle-sensitive pixels. Such image sensors include two diffraction gratings patterned over and in parallel with an array of photosensors. The spacing between the gratings is important, and can be difficult to obtain reliably using inexpensive and readily available fabrication processes. Moreover, the gratings are sensitive to the wavelength of incident light in a wavelength band of interest, making it difficult to accurately reproduce color images.
The figures are illustrations by way of example, and not by way of limitation. Like reference numerals in the figures refer to similar elements.